Brief Description: Final fitting/dimpling of trim tab spar-to-hinge
Since the trim tab spar is quite thin, countersinking for the flush rivets will open the holes larger than the pilot, so a back-up strip must be used (to keep the C/S bit from 'wandering' all over the place when the hole is countersunk, since the 'pilot' would be 'lost'). I used a piece of angle AL, match-drilled & clecoed to the tab spar. After this, one-by-one the holes were countersunk for flush rivets so the spar would accept the dimples from the trim tab skin. The trim tab hinge then 'sandwiches't the trim tab spar to the skin.